A comparison of isometric exercise, cold pressor stimulation and dynamic exercise in patients with coronary heart disease

Isometric exercise and cold pressor stimulation have been proposedas alternatives to dynamic exercise in the evaluation of patientswith coronary heart disease. We evaluated all three, by gatedradionuclide ventriculo-graphy, in 13 male controls and 44 malepatients with coronary heart disease. In controls, mean leftventricular ejection fraction did not change during isometricexercise or cold pressor stimulation (64±2 to 63±2and 63 ± 3) but fell significantly in patients (56±1to 53±I and 53±1, both P < 0·001). Duringdynamic exercise, mean left ventricular ejection fraction rosein controls (64±2 to 84±2, P<0·001)but did not change in patients (56±1 to 56 ±2).There was considerable overlap between the groups in the leftventricular ejection fraction response to isometric exerciseand cold pressor stimulation; only dynamic exercise discriminatedbetween them. Isometric exercise and cold pressor stimulationare of little value in the diagnosis of coronary heart diseaseby radionuclide ventriculography.     

The differing prognostic utility of exercise radionuclide ventriculography in coronary artery disease patients with and without prior myocardial infarction

Previous studies have documented the prognostic utility of left ventricular ejection fraction response to exercise primarily in populations without prior myocardial infarction. We undertook a study to assess the prognostic utility of exercise left ventricular ejection fraction and segmental wall motion response during exercise radionuclide ventriculography in coronary artery disease patients with and without prior myocardial infarction. Methods. We examined the comparative prognostic utility of left ventricular ejection fraction and segmental wall motion response during upright bicycle exercise radionuclide ventriculography in 419 coronary artery disease patients with (n=217) and without (n=202) prior myocardial infarction using univariate and multivariate hierarchical regression analyses. Results. During an average followup period of 61 months, 96 patients (23%) suffered cardiac events, including 55/217 (25%) of the patients with prior myocardial infarction and 41/200 (21%) of the patients without prior myocardial infarction (p=ns). Both cumulative Kaplan-Meier survival analyses and stepwise hierarchical Cox survival analyses demonstrated that peak left ventricular ejection fraction <55% was a significant predictor of cardiac events in patients without prior myocardial infarction (p=0.04), whereas an exercise wall motion worsening score 2 was a significant predictor in patients with a prior myocardial infarction (p=0.0001). Conclusions. The prognostic utility of exercise radionuclide ventriculography variables differ according to the presence or absence of prior myocardial infarction. Global function, assessed by peak left ventricular ejection fraction, adds the greatest prognostic information in patients without prior myocardial infarction, whereas regional function, assessed by exercise wall motion worsening, is the best predictor among patients with prior myocardial infarction.     

运动锻炼为核心的家庭心脏康复项目对慢性心力衰竭患者康复治疗效果影响的临床研究

目的 探讨运动锻炼为核心的家庭心脏康复项目对慢性心力衰竭（chronic heart failure, CHF）患者心脏康复治疗效果的影响。方法 选择2015年1月至2019年1月间在北京康复医院临床诊断为CHF患者48 例,随机分为四组：对照组（12例）：进行除运动锻炼治疗之外的常规心脏康复指导;医院功率车组（12例）;家庭功率车组（12例）：患者分别在医院和家庭内进行功率车锻炼;家庭普通运动组（12例）：家庭内运动,运动方式可采用游泳、慢跑、快走、骑自行车等方式。三组运动组患者采用12周运动锻炼为核心的整体管理。治疗前、后分别评估患者运动心肺功能、心脏超声、6 min步行距离（6 minute walking distance, 6MWD）、Minnesota心力衰竭生活质量（quality of life, QoL）评分等。结果 12周康复治疗后,医院功率车组、家庭功率车组和家庭普通运动组患者峰值摄氧量［（19.5±4.4）ml·min-1·kg-1、（18.5±3.1）ml·min-1·kg-1、（17.0±1.9）ml·min-1·kg-1比（13.2±2.0）ml·min-1·kg-1,P<0.05］、左心室射血分数［（44.6±3.9）%、（44.3±8.7）%、（43.6±5.0）%比（37.8±5.7）%,P<0.05］和6MWD［（502.6±95.8）m、（482.1±54.5）m、（448.4±51.6）m比（383.5±77.1）m,P<0.05］均较对照组明显升高;同时QoL评分［14.8±7.9、12.9±6.8、19.1±8.7比43.2±10.8,P<0.05］均较对照组明显降低。组间比较显示,家庭普通运动组患者峰值摄氧量较医院功率车组降低（P<0.05）。治疗前后比较显示,12周康复管理后,医院、家庭功率车组和家庭普通运动组患者峰值摄氧量、左心室射血分数和6MWD均比治疗前升高（P<0.05）,QoL评分较治疗前降低（P<0.05）。结论 家庭运动康复为核心的整体管理,包括功率车和普通运动,可显著改善CHF患者心肺功能、运动耐力和生活质量,家庭康复作为心脏康复一种有效的治疗模式,值得大力推广。     

心脏运动康复对PCI术后冠心病患者心肺功能及生活质量的影响

目的评价心脏运动康复对冠心病经皮冠状动脉介入治疗(PCI)术后患者心肺功能及生活质量的影响。方法入选确诊并已行PCI出院的冠心病患者110例,按个人意愿分为康复组和对照组各55例,收集患者的一般资料、入选时和运动治疗6月后心肺运动试验、心脏超声的相关指标及西雅图心绞痛量表(SAQ)等数据,并进行统计学分析,评估心脏运动康复对冠心病PCI术后患者心肺功能及生活质量的影响。结果 6个月运动康复治疗后,康复组患者无氧阈(AT)、最大摄氧量(VO2max)、氧脉搏(O2pulse)、最大运动时间、左心室射血分数(LVEF)、SAQ评分均优于干预前与对照组,差异有统计学意义(P0. 05)。结论心脏运动康复治疗可以改善冠心病PCI术后患者的心肺功能,提高患者的运动耐力及生活质量,是冠心病PCI术后患者二级预防的重要组成部分。     

Mitral valve prolapse in the ventriculogram: scintigraphic, electrocardiographic, and hemodynamic abnormalities

Patients with mitral valve prolapse (MVP) frequently have chest pain, which may be difficult to differentiate from angina pectoris in coronary artery disease (CAD). We performed resting and exercise ECGs, pulmonary arterial pressure measurements, radionuclide ventriculography (99mtechnetium), and perfusion scintigrams (201thallium) in 56 patients with angiographically proven MVP and no CAD. Pathological results were obtained in 31% of exercise ECGs, 33% of pulmonary arterial pressure measurements during exercise, 22% of radionuclide ventriculographies, and in 75% of thallium perfusion scintigrams. A significant correlation in pathological results was found only between exercise ECG and both radionuclide ventriculography and pulmonary arterial pressure measurements. Because of the high prevalence of false-positive perfusion scintigrams in patients with typical or atypical chest pain, the use of exercise 201Tl imaging as a screening method to separate patients with MVP from those with CAD will not be appropriate. The variability of cardiac abnormalities in our patients with MVP and angiographically normal coronary arteries suggests that the MVP syndrome may represent a variable combination of metabolic, ischemic, or myopathic disorders.     

Gas exchange threshold to guide exercise training intensity of older individuals during cardiac rehabilitation

The gas exchange threshold (GET), which is determined during incremental exercise (Inc-Ex) testing, is often considered a safe training intensity for cardiac rehabilitation. However, there are only a limited number of reports on the actual implementation of this method. We assessed the applicability of GET-guided exercise using a constant load exercise (CL-Ex) protocol.We recruited 20 healthy older individuals (healthy, age: 69.4 ± 6.8 years) and 10 patients with cardiovascular diseases or risk factors (patient, age: 73.0 ± 8.8 years). On day 1, we determined the GET during symptomatic maximal Inc-Ex. On day 2, CL-Ex at work rate (watt: W) where the GET manifested during Inc-Ex (therefore, not corrected for the known oxygen response delay) was maintained for 20 minute. Arterialized blood lactate (BLa) levels were also determined.Oxygen uptake reached a steady state in all participants, with a mean respiratory exchange ratio of < 1.0. The mean BLa at the GET during Inc-Ex was 1.51 ± .29 mmol·l⁻¹ in the healthy group and 1.78 ± .42 mmol·L⁻¹ in the patient group, which was about .5 mmol·L⁻¹ above the resting level. During CL-Ex, BLa increased significantly over the value at the GET (Inc-Ex). However, it reached a steady-state level of 2.65 ± 1.56 (healthy) and 2.53 ± 0.95 (patient) mmol·L⁻¹. The %peak oxygen uptake, %peak heart rate, and %heart rate reserve during CL-Ex were 58.8 ± 11.5, 71.8 ± 10.3, and 44.9 ± 17.4, respectively. All participants could complete CL-Ex with mean perceived exertion ratings (Borg/20) of 11.8 ± 1.3 (healthy) and 12.2 ± 1.3 (patient). These heart rate-related indices and exertion ratings were all within the recommended international guidelines for cardiac rehabilitation.CL-Ex at the GET appears to be the optimal exercise intensity for cardiac rehabilitation.     

The effects of aging after coronary arterial bypass grafting on the regulation of cardiac output during upright exercise

We examined the effects of age on cardiac performance and the mechanisms that regulate cardiac output during upright exercise in patients free of myocardial ischemia after coronary revascularization. There were 90 subjects, aged 36 to 75 years, of whom 27 were greater than or equal to 60 years. There were no age-related changes in resting heart rate, systolic blood pressure, left ventricular end-diastolic volume index, left ventricular end-systolic volume index, stroke volume index, cardiac index and left ventricular ejection fraction. There were, however, age-related changes in exercise capacity (y = 20 - 0.21x, r = -0.52, P less than 0.001); exercise heart rate (y = 185 - 1x, r = -0.42, P less than 0.001); exercise end-systolic volume index (y = 11 + 0.46x, r = 0.28, P less than 0.01) and exercise ejection fraction (y = 81 - 0.31x, r = -0.28, P less than 0.01). In a subgroup of 54 patients with comparable exercise workload (27 aged less than 60 and 27 greater than or equal to 60 years), the age-related differences in exercise end-systolic volume index, exercise ejection fraction and exercise cardiac index were not observed, but the exercise heart rate was still higher in the younger patients (y = 168 - 0.76x, r = -0.34, P less than 0.01). Thus, age modifies the compensatory mechanisms that regulate the cardiac output during exercise. Young and old patients alike show increases in end-diastolic volume and ejection fraction to maintain exercise cardiac output. The higher exercise heart rate in the younger subjects suggests a decrease in cardiac responsiveness to adrenergic stimulation associated with aging.     

A Computerized approach to evaluating rest and exercise-induced ecg/vcg changes after cardiac rehabilitation

Summary: A computerized method of acquiring and analyzing rest and exercise test 12-lead electrocardiographic and three-dimensional lead vectorcardiographic data before and after cardiac rehabilitations is described. Fourteen coronary heart disease patients were exercise tested before and after a mean of five months of aerobic exercise training. The only significant ST-segment improvements were found in three-dimensional space. Spatial measurements should be considered in the assessment of electrocardiographic changes secondary to exercise training.     

True-positive exercise electrocardiogram/false-negative thallium-201 scintigram: a proposal of a mechanism for the paradox

A 72-year-old man with exertional angina had a strongly positive exercise electrocardiogram (EECG) with a negative thallium-201 myocardial perfusion scintigram (Tl). Arteriography revealed triple-vessel coronary artery disease, for which he underwent aortocoronary bypass grafting. Repeat EECG was negative, and it was again associated with a negative Tl. The false-negative Tl on the first test was felt to be due to a rare phenomenon of homogeneously distributed reversible exercise-induced myocardial ischemia, leading to a uniform radiotracer count density. The even distribution of ischemia would also be expected to render a false-negative EECG, due to electrocardiographic cancellation, and this is frequently the case. However, in the patient presented herein, we propose that the ischemic cardiac apex rendered the EECG strongly positive because its position was not opposed by an ischemic muscular region, and thus an uncancelled ischemic ST-segment vector was generated. This hypothesis is supported by our recent work showing the unique role of the ischemic apex (among all the other myocardial territories) in rendering the EECG positive.     

Efficacy of intravenous dipyridamole with exercise in thallium-201 myocardial perfusion scintigraphy

To assess the feasibility and the value of thallium–201myocardial perfusion imaging with intravenous dipyridamole incombination with low-level exercise, 81 patients with suspectedor proven coronary artery disease were studied. All patientsunderwent coronary arteriography. Significant coronary arterydisease (stenoses 50%) was present in 59 patients (73%); multivesseldisease (double- and triple-vessel desease) was observed in33 patients (42%). The overall sensitivity and specificity ofthe test were 78% and 86%, respectively. Sensititvity and specificityfor detection of multivessel disease were 70% and 92%, respectively.The sensitivity for detecting coronary artery disease in theRCA, LAD, and LCX was 74%, 82% and 48%, respectively, and thespecificity was 85%, 88% and 88%, respectively. With the combinedprocedure no serious side effects were observed. Mild side effectslike headche, vertigo and uausea were seen in 12 patients (15%). Twenty volunteers with a 1% likelihood of significant coronaryartery disease were examined in the same manner to determinethe maximal specificity of the procedure (100%). Thus, the combinationof two different stress procedures (exercise testing and dipyridamoleinfusion) can be performed safely without serious side effects.The presence, location and extent of significnt coronary arterydisease can be assessed to a similar degree as with conventionalexercise thallium-201 scintigraphy, which has major implicationsfor the detection of coronary artery disease in patients whoare unable to perform maximal exercise.     

Prognostic value of supine scintigraphic heart function and simultaneous conventional exercise response in patients after myocardial infarction

A total of 240 survivors of one or more myocardial infarctions were consecutively admitted to perform supine exercise radionuclide ventriculography. Within 3 years after the test, 22 died; this group was compared to an age-matched control group of 22 survivors for left and right ventricular function during rest, exercise, and simultaneously assessed exercise performance as well as ECG variables. Evaluation of 3-year survival by linear discriminant analysis revealed an accuracy of 82% for discriminant models using ECG and exercise performance variables. Implementation of resting left ventricular ejection fraction and change of right ventricular ejection fraction during exercise, as well as scintigraphic presence or absence of dyskinesia, improved the accuracy of the model to 91% of correctly classified patients.     

居家心脏康复和中心心脏康复对冠心病患者心肺适能的影响

目的 探索居家心脏康复(HBCR)和中心心脏康复(CBCR)对冠心病(CHD)患者心肺适能的影响.方法 选取2018年11月至2019年10月在解放军总医院心脏康复中心门诊就诊的18～80岁的CHD患者,采用随机数表和信封法将患者分为HBCR组和CBCR组,分别以HBCR或CBCR干预3个月.对比2组患者干预前后的峰值...     

The role and outcome of cardiac rehabilitation program in patients with atrial fibrillation

Background

Atrial fibrillation (AF) is associated with diminished cardiac function, and exercise tolerance.

Hypothesis

We sought to investigate the role of cardiac rehabilitation program (CR) in patients with AF.

Methods

The study included 2165 consecutive patients that participated in our CR program between the years 2009 to 2015. All were evaluated by a standard exercise stress test (EST) at baseline, and upon completion of at least 3 months of training. Participants were dichotomized according to baseline fitness and the degree of functional improvement. The combined primary end point was cardiac related hospitalization or all‐cause mortality.

Results

A total of 292 patients had history of AF, with a mean age of 68 ± 9 years old, 76% of which were males. The median predicted baseline fitness of AF patients was significantly lower compared to non‐AF patients (103% vs 122%, P < 0.001, respectively). Prominent improvement was achieved in the majority of the patients in both groups (64% among AF patients and 63% among those without AF). Median improvement in fitness between stress tests was significantly higher in patients with AF (124% vs 110%, P < 0.001, respectively). Among AF patients, high baseline fitness was associated with a lower event rates (HR 0.40; 95%CI 0.23‐0.70; P = 0.001). Moreover, prominent improvement during CR showed a protective effect (HR 0.83; 95% CI 0.69‐0.99; P = 0.04).

Conclusion

In patients with AF participating in CR program, low fitness levels at baseline EST are associated with increased risk of total mortality or cardiovascular hospitalization during long‐term follow‐up. Improvement on follow‐up EST diminishes the risk.     

Prognostic value of predischarge radionuclide ventriculography at rest and exercise after acute myocardial infarction treated with thrombolytic therapy or primary coronary angioplasty

Background: Previous studies have demonstrated the prognostic value of radionuclide ventriculography at rest and exercise in patients post myocardial infarction (MI). The number of studies in patients treated with modern reperfusion techniques, including thrombolysis or primary angioplasty, however, is limited. Hypothesis: The aim of this study was to evaluate the prognostic significance of predischarge radionuclide ventriculography at rest and exercise in patients with acute MI treated with thrombolysis or primary angioplasty. Methods: A total of 272 consecutive patients with acute MI who were randomized to thrombolysis or primary coronary angioplasty underwent predischarge resting and exercise radionuclide ventriculography. Left ventricular ejection fraction at rest, decrease in ejection fraction during exercise >5 units below the resting value, angina pectoris, ST-segment depression, and exercise test ineligibility were related to subsequent cardiac events (cardiac death, nonfatal reinfarction) during follow-up. Results: During a mean follow-up of 30 ± 10 months, cardiac death occurred in 11 (4%) patients and nonfatal reinfarction in 14 (5%) patients. Resting left ventricular ejection fraction was the major risk factor for cardiac death. In patients with an ejection fraction <40%, cardiac death occurred in 16% compared with 2% in those with an ejection fraction ≥ 40% (p = 0.0004). In addition, cardiac death tended to be higher in patients ineligible than in those eligible for exercise testing (11 vs. 3%, p = 0.08). None of the other exercise variables (decrease in ejection fraction during exercise >5 units below the resting value, angina pectoris or ST-segment depression) were predictive for cardiac death. When all exercise test variables in each patient were combined and expressed as a risk score, a low risk (n = 185) and a higher risk (n = 87) group of patients could be identified, with cardiac death occurring in 1 and 10%, respectively. As the predictive accuracy of a negative test was high, radionuclide ventriculography was of particular value in identifying patients at low risk for cardiac death. Radionuclide ventriculography was not able to predict recurrent nonfatal MI. Conclusion: In patients with MI treated with thrombolysis or primary angioplasty, radionuclide ventriculography may be helpful in identifying patients at low risk for subsequent cardiac death. In this respect, left ventricular ejection fraction at rest was the major determinant. Variables reflecting residual myocardial ischemia were of limited prognostic value. Identification of a large number of patients at low risk allows selective use of medical resources during follow-up in this subgroup and has significant implications for the cost effectiveness of reperfusion therapies.     

Thallium-201 scintigraphy after dipyridamole infusion with low level exercise. II. Quantitative analysis vs visual analysis

To determine the value and limitations of quantitative analysis of thallium-201 imaging after intravenous dipyridamole in combination with low level exercise, 81 patients with suspected coronary artery disease (CAD) were evaluated prospectively. The results of quantitative analysis were compared with the results of visual analysis. All patients underwent coronary arteriography and left ventricular angiography. Significant CAD was present in 59 patients (73%); multivessel CAD was observed in 33 patients (42%). Mild side-effects such as headache, vertigo and nausea were experienced by 12 patients (15%). To establish 'test-specific' normal limits in quantitative analysis of uptake and washout of thallium-201 after dipyridamole infusion with low level exercise we studied 20 healthy volunteers with a likelihood of CAD less than or equal to 1%. Sensitivity and specificity of quantitative analysis for overall detection of significant CAD were 76% and 73%, respectively vs 78% and 86%, respectively with visual analysis (P = NS). Sensitivity for the detection of multivessel CAD was slightly higher with quantitative analysis (73%) than with visual analysis (70%), but the specificity was lower (75% vs 92%) (P = NS). Sensitivity of quantitative analysis in relation to vessels involved was slightly lower than with visual analysis (RCA and LAD: P = NS; LCX: P less than 0.05). Of 14 patients with false-negative results, four had multivessel CAD. Thus, quantitative analysis after the combination of dipyridamole infusion with low level exercise did not improve the diagnostic value as assessed by semi-quantitative visual analysis.     

Prevalence and clinical outcomes of patients with apparent treatment‐resistant hypertension enrolled in Phase 2 cardiac rehabilitation

Phase 2 cardiac rehabilitation (CR) employs evidenced‐based interventions to modify the risk of cardiac morbidity in its participants. The prevalence of apparent treatment‐resistant hypertension (aTRH) among CR participants is unknown. A retrospective analysis of a longitudinal cohort of patients who completed CR between 2012 and 2017 was undertaken. The prevalence of hypertension was 62% (n = 311). 11% of participants with hypertension had aTRH (n = 35). Participants with aTRH exhibited lower exercise capacity (EC) before starting CR and after its completion compared to normotensive counterparts (P < .001). aTRH participants were more likely to experience a decrease in EC, even after participating in cardiac rehabilitation, compared to normotensive participants (P = .02). aTRH participants were more likely to be hospitalized or seen in the emergency department after cardiac rehabilitation completion compared to normotensive counterparts (OR: 2.85, P < .01). CR presents an opportunity to identify and appropriately care for patients with aTRH.     

Determinants of exercise capacity in patients with coronary artery disease and mild to moderate systolic dysfunction: Role of heart rate and diastolic filling abnormalities

BACKGROUND: To test the hypothesis that diastolic filling abnormalitiesare an important cause of exercise limitation in some patientswith coronary artery disease we assessed the factors limitingexercise capacity in a group of patients with coronary arterydisease in whom exercise limitation was greater than expectedfrom the degree of resting left ventricular systolic dysfunction. METHODS AND RESULTS: We assessed the relationship between exercise capacity (maximaloxygen consumption) during erect cycle ergometry, heart rate,radionuclide indi ces of left ventricular systolic function(ejection fraction) and diastolic filling (peak filling rate,and time to peak filling) during semi-erect cycle ergometryin 20 patients (15 male, five female) who were aged 42–72years (mean 61 years) and had angiographically proven coronaryartery disease and evidence of reversible myocardial ischaemiaon thallium scintigraphy. All patients exhibited marked exerciselimitation (maximal oxygen consumption 8.7–22.4 ml. min^–1.kg^–1— mean 15.9 ml. kg^–1. min^–1, whichwas 611 ± 16% of age and gender predicted maxi mum) dueto breathlessness or fatigue rather than angina, in spite ofa mean ejection fraction for the group of 465% (range 30–67%).We also compared the diastolic filling characteristics of thesepatients during exercise with 10 healthy controls (age 38–66,mean 58 years; eight male, two female). Comparing diastolicfilling characteristics, peak filling rate was higher and timeto peak filling shorter both at rest and peak exercise in controlsthan patients (peak filling rate 3.1± 0.5 vs 2.2±0.9 EDV. s^–1 P =0.01 at rest and 8.3± 0.8 vs 5.2±1.9 EDV. s^–1 , P< 0.0000l on exercise; time to peakfilling 115.2± 29.8 vs 228.9± 71.7 ms, p< 0.0001.atrest and 52.8± 16.2 vs 139.6± 4.48 ms, P<0.0000lon exercise respectively). On univariate analysis in the patientsstudied, maximal oxygen consumption was correlated with peakheart rate (r=0.45 P=0.04), peak exercise time to peak filling(r=– 0.85 P< 0.0001 peak exercise peak filling rate(r = 0.58, P=0.019), and the relative increase in cardiac outputi.e. cardiac output peak/cardiac output rest (r=0.58, P=0.008).There was no correlation between maximal oxygen consumptionand resting indices of diastolic filling (peak filling rateand time to peak filling) or with resting or peak exercise ejectionfraction. On multiple regression analysis, only peak exercisetime to peak filling was significantly related to maximal oxygenconsumption. CONCLUSION: We have observed a strong correlation between exercise capacityand indices of exercise left ventricular diastolic filling,and have confirmed previous studies showing a poor correlationwith resting and exercise indices of systolic function and restingdiastolic filling, in patients with coronary artery disease.